Reversing apparatus for powered vehicle door systems

ABSTRACT

An obstruction detecting reversing apparatus is disclosed for a motor driven device, such as a powered vehicle door or window system, wherein the device undergoes varying loads, and consequently varying current draws, during normal operation. In order to accurately detect the presence of an obstruction, in light of such normally varying currents, the apparatus circuit logic monitors instantaneous motor current and compares it with the time average of motor current over a very short preceding time interval, which &#34;tracks&#34; normal current draw in order to sense an obstruction-caused rise in motor current at virtually any stage of the door closing operation, and thus also accommodates normal changes in current draw caused by different gravity effects when the device is oriented in different grade-caused orientations.

CROSS REFERENCE TO RELATED PATENTS AND APPLICATIONS

This invention is related to the inventions disclosed and claimed inU.S. Pat. Nos. 4,887,390; 4,862,640; 4,842,313; and 4,775,178, all ofwhich are assigned to the same assignee as the present invention, andthe disclosures which are hereby incorporated by reference herein. Thisinvention is also related to the inventions disclosed and described inrelated copending applications for U.S. Patents, entitled "VARYINGRADIUS HELICAL CABLE SPOOL FOR POWERED VEHICLE DOOR SYSTEMS", "CONTROLAPPARATUS FOR POWERED VEHICLE DOOR SYSTEMS", and "POWERED CLOSING ASSISTMECHANISM FOR VEHICLE DOORS OR LID MEMBERS", all of which are filed onthe same date as this application and are assigned to the same assigneeas the present invention, and the disclosures of which are herebyincorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a reversing apparatus for motor-actuateddevices for detecting a predetermined abnormal load on such devices andfor stopping and reversing the drive motor in response to the presenceof such abnormal load, such as the presence of an obstruction. Thereversing apparatus is especially applicable to powered sliding dooroperating systems for vehicles and, more particularly, to such poweredsliding door operating systems for van type vehicles having a dooropening in a side wall of the van. In such applications of theinvention, the sliding door is moved generally parallel to the van sidewall during its initial closing movement and for a major portion of itsfull closing movement as well as during a major portion of its fullopening movement, including its final opening movement. Typically, thesliding door moves generally toward and generally away from the plane ofthe door opening during a portion of its respective final closing andinitial opening movements, so as to be flush with the side wall whenfully closed, and so as to be alongside of, and parallel to, the sidewall, generally rear of the door opening, when fully opened.

In sliding door systems of the type mentioned above, upper and lowerforward guide rails are attached to the top and bottom portions,respectively, of the door opening, and a rear guide rail is attached tothe exterior of the side wall, at an elevation approximately midwaybetween the elevation of the upper and lower forward guide rails. Therespective forward end portions of the various guide rails are curvedinwardly of the body of the van, and bracket and roller assemblies arefastened to the respective upper and lower forward ends of the slidingdoor, as well as to an intermediate position at the rear end of thesliding door. Such bracket and roller assemblies are slidingly supportedin the guide rails to guide the door through its opening and closingmovements.

Various portions of the opening and closing movements of van slidingdoors have different power requirements. Thus, the initial door closingmovement and a major portion of the subsequent door closing movement arehigh displacement/low force translational movements, during which littleforce is required to achieve large door movements since only frictionalresistance and grade-caused gravity resistances must be overcome.Similarly, the final opening movement and a major portion of thepreceding opening movement are also high displacement/low forcetranslational movements for the same reasons. In contrast however, aportion of the final closing movement of the door is a lowdisplacement/high force movement. This is because during final closing,an elastomeric weather seal surrounding the door opening must becompressed, and an unlatched latch bolt on the door must engage and berotated to a latched position by a striker pin at the rear of the vanbody door opening. During manual operation, sliding van doors aretypically moved with great momentum through their entire closingmovements in order to assure full weather strip compression and latchbolt operation at the end of such movement.

Various powered van door systems have been developed in the past,including those described in the above-mentioned related U.S. patents.Another such system is illustrated in U.S. Pat. No. 4,612,729, issued toSato. In the Sato patent, a motor driven pinion carried by the lowerfront bracket and roller assembly of the door cooperates with a rackgear carried by the lower front guide rail in the door opening to movethe door between its fully open and fully closed positions. In thisarrangement, as in the case of the manual door operation discussedabove, a high momentum is still required during the entire closingmovement.

Similarly, U.S. Pat. No. 4,617,757, issued to Kagiyama et al, and U.S.Pat. No 4,640,050, issued to Yamagishi et al also represents additionalexamples of powered van door systems. The systems employ cable drivescoupled to the lower front bracket and roller assemblies of the doorsfor opening and closing movements However, these systems also rely onhigh momentum during the entire closing movement.

U.S. Pat. No. 4,462,185 issued to Shibuki et al describes still anotherpowered van door system. In this system, a friction wheel engages thebottom portion of the door and drives the door through the majorportions of its opening and closing movements parallel to the side wallof the van. Turntable arms are pivotably connected end-to-end betweenthe friction wheel and the floor of the door opening and draws the rearof the door inwardly to compress the weather strip, While this prior artdesign appears to operate with lower momentum forces during closingmovement than those discussed above, it requires a complicated, costlymechanism that is difficult to install and difficult to repair in theevent of a breakdown. Moreover, retrofiting this mechanism to a vehiclenot originally equipped with a powered door system would be inordinatelydifficult.

In addition to the foregoing prior art systems, final closing devices orclamping mechanisms for powering the final, low-displacement/high-forcemovement of sliding van doors have been developed by the assignee of thepresent invention and are described in the above-mentioned U.S. Pat.Nos. 4,775,178 and 4,842,313, the disclosures of which are incorporatedby reference herein. In each of these systems, the door includes a latchbolt member moveable between latched and unlatched positions, as well asa handle or a lock member movable between open and closed positions. Thefinal closing device or clamping mechanisms each includes a strikersupport plate mounted on the vehicle body at the rear of the dooropening for rotational movement about a perpendicular axis, a strikerpin projecting from the striker support plate at a position offset fromthe axis, and means carried by the vehicle body for rotating the strikersupport plate. The striker pin is movable between extended and retractedpositions so that when the striker pin is engaged by the latch memberbolt the striker support plate is rotated, and the sliding door is movedbetween a partially open position away from the door opening and a fullyclosed position. In addition to disclosing the foregoing structure, U.S.Pat. No 4,842,313 also discloses a crashworthiness feature that adds apawl and ratchet mechanism to prevent the striker support plate frombeing reversely rotated in response to high door opening forces from theinside of the vehicle.

Although U.S. Pat. Nos. 4,775,178 and 4,842,313 illustrate excellentfinal closing systems for sliding van doors, they do not includeprovisions for powering van doors through the major portions of openingand closing movements, nor do they include provisions for powering vandoors during late closing movements to the point where the latch boltmechanisms engage with, and close about, the striker pins of theclamping mechanisms.

Improved powered sliding door operator systems for van type vehicles aredisclosed in the above-mentioned U.S. Pat. No. 4,862,640, with thedisclosed systems having provisions (i) for powering sliding van doorsthrough the major portions of opening and closing movements, (ii) forpowering sliding van doors during late closing movements to engage thelatch bolt mechanisms with the striker pins, and (iii) for finallyclamping sliding van doors to a fully closed position. In such patentthe disclosure of which is hereby incorporated by reference, the door issupported adjacent its forward end by forward brackets slidable in upperand lower forward guide members carried by the vehicle body, and issupported adjacent its rear end by a rear bracket slidable in amid-level rear guide member carried on the outside of the vehicle sidepanel. Motor driven cable members are attached to the rear bracket andsupported adjacent opposite ends of the rear guide member and areemployed to move the door through its opening movement through itsinitial closing movement, and through an initial portion of its finalclosing movement. The final portion of its closing movement isaccomplished using a final clamping mechanism of the type disclosed inthe above-mentioned U.S. Pat. No. 4,842,313.

It is therefore, a primary object of the present invention to provide animproved powered sliding door operator system for van type vehicles inwhich the sliding door is moved with low momentum between its fully openposition and its nearly closed position, and which completely closes thesliding door in a slow controlled manner.

Another object of this invention is to provide an improved poweredsliding door operator system in which the manual effort required to openand close the sliding door is substantially reduced, in whichnear-normal manual operation of the sliding door is preserved in theevent of a failure of the powered system, and in which the poweredsystem can be actuated from either the vehicle driver's seat or the dooritself.

A primary object of the present invention is to provide a mechanism orsystem capable of detecting an obstruction encountered by a moving door,or other moving member in other powered actuating devices, such aspowered vehicle windows, for example, and then stopping and/or reversingsuch motion in order to prevent damage to the obstruction, to the movingdoor or other member, or to the powered actuating equipment.

Still another related object of the invention is to accomplish theabove-mentioned obstruction detection and motion reversing within apredetermined, acceptable time, within a predetermined obstructionresistance force when the moving door or member is disposed within apredetermined range of angular positions (such as those resulting from avehicle situated on an upwardly or downwardly inclined grade), andwithin a predetermined temperature range likely to be encountered by thepowered vehicle door system or other powered actuating system.

In accordance with one exemplary embodiment or application of theinvention, a powered door operator system is provided for a doorslidingly supported relative to a door opening in a side panel of avehicle body. The door is supported adjacent its forward end by at leastone forward bracket that is slidable in a forward guide member andadjacent its rear end by a rear bracket that is slidable in a rear guidemember. The guide members guide the door (i) through an initial closingmovement generally parallel to the side panel (ii) through a finalopening movement generally parallel to the side panel, (iii) through atleast a portion of its final closing movement generally toward the planeof the door opening, and (iv) through at least a portion of its initialopening movement generally away from the plane of the door opening. Thedoor operator system includes cable members coupled to the forward andrear ends of the door for driving the door along the guide members tothereby move the door through its initial and final opening and closingmovements, substantially without the need for cable spool assemblytensioning mechanisms.

An improved cable spool arrangement is provided in such exemplaryapplication of the invention for a cable-actuated device, such as for apowered van door system, for example, having a drive mechanism forselectively rotating the cable spool about an axis in either directionand one or more cables each having one end interconnected with a movablemember, such as a sliding door. The cable spool includes a cableattachment arrangement for securing the opposite end or ends of thecable or cables to the cable spool. A groove, slot, or other openchannel-like opening is formed along a generally helical path on acircumferential portion of the cable spool. The groove is adapted forwindingly receiving or taking up at least one of the cables therein asthe cable spool is rotated in one direction, and for unwindinglyreleasing or paying out at least one of the cables therefrom as thecable spool is rotated in the opposite direction. The helicalconfiguration of the cable spool groove eliminates the undesirableconstantly changing effective spool radius that results from cablewrap-up or stacking on cable spools having one or more circular ornon-helical grooves. Thus, the cable take-up and pay-out rates relativeto cable spool rotation, can be more closely defined and controlled.

In addition, in the preferred cable spool in such exemplary application,the radial depth (and thus the wrap-up and pay-out radius) of thehelical groove varies along at least a portion of the helical path inorder to cause at least one of the cables to be wound onto, and paid outfrom, the varying-depth portion of the helical groove at acorrespondingly varying rate with respect to cable spool rotation. Thiseffect can be used to cause movement of at least a portion of thesliding door, or other such movable member, at a correspondingly varyingrate with respect to cable spool rotation. If desired in a givenapplication, the cable spool can have a generally constant radial depthof the helical groove along second portion of the helical path in orderto cause at least one of the cables to be wound onto, and paid out from,the constant-depth portion of the helical groove at a generally constantrate with respect to cable spool rotation. This effect can be used tocause movement of at least a portion of the sliding door or othermovable member, at a generally constant rate with respect to cable spoolrotation.

In accordance with the present invention, a reversing apparatus isprovided for detecting the presence of an obstruction encountered by themovable door, or other movable member such as a power window, forexample, and causing a stoppage and/or reversal of its motion in orderto substantially prevent damage to the obstruction, the door or othermovable member, or the powered actuating system. The reversal apparatususes changes in drive motor currents during door actuation that indicatethe presence of an obstruction by comparing the instantaneous motorcurrent with a reference current that is averaged over a predeterminedshort time interval This feature makes the reversing apparatusindependent of the normally varying drive motor current, with suchnormal variance resulting from the changes in the types of door closingmovements described above. Thus, the reversing apparatus properly sensesor detects the presence of an obstruction even for van-type slidingdoors or other movable powered-actuated members, that undergo varying orcomplex movements, or changing relationships between travel speed andforce at various stages of their operation, and that draw differentamounts of drive motor current when disposed in different angular, orgrade-caused, orientations.

Additional objects, advantages, and features of the present inventionwill become apparent from the following description and appended claims,taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, with parts broken away for clarity, of avan-type vehicle having a powered sliding door operating system inaccordance with the present invention.

FIG. 2 is a view similar to FIG. 1 with parts broken away for clarity,showing the sliding door of the van in a partially open position.

FIGS. 3, 4, and 5 are each diagrammatic views, illustrating the path ofmovement followed by the sliding door relative to its supporting guiderails during closing of the door.

FIG. 6 is a perspective view of a portion of the interior of the vanshown in FIGS. 1 and 2 with parts broken away for clarity, illustratingan embodiment of the invention in which a cable or cables are coupled tothe forward end of the sliding door and to the rear end of the slidingdoor, and are actuated by an improved cable spool assembly according tothe invention.

FIG. 7 is an enlarged detailed perspective view of a portion of thesystem illustrated in FIG. 6 showing the preferred manner in which acable is fastened to a rear bracket and roller assembly carried at therear end of the door.

FIG. 8 is a perspective view of the interior of the van, similar to thatof FIG. 6, but viewed from a different point inside the vehicle andshowing the door in a partially open position.

FIG. 9 is an enlarged perspective view, illustrating one preferredembodiment of a cable spool assembly according to the present invention.

FIG. 10 is a perspective view of the cable spool and portions ofassociated cables of FIG. 9.

FIG. 11 is a top view of the cable spool, and portions of associatedcables, of FIGS. 9 and 10.

FIG. 12 is a radially-cut, cross-sectional view of the cable spool ofFIGS. 9 through 11.

FIG. 13 is a plot of effective groove radius versus angular position ofone preferred exemplary cable spool of FIGS. 9 through 12.

FIG. 14 is a sectional view, taken along the line 14--14 of FIG. 8,showing the locations of push button switches used in controlling theoperation of the sliding door in one form of the powered door system.

FIGS. 15A and 15B are fragmentary perspective views of a limit switcharrangement in the upper forward guide of the sliding door, which isactuated and deactuated when the door reaches a predeterminedintermediate point during its movement between its fully opened andclosed positions.

FIG. 16 is an exploded perspective view of one form of a final closureor clamping mechanism employed to move the nearly closed sliding door toits fully closed position.

FIGS. 17, 18, and 19 are enlarged sectional views, taken through amechanism in FIG. 16 for precluding reverse rotation of the strikerplate, and showing the relationship of a pawl to a single tooth ratchetwheel thereof when the striker pin is in its extended position, in itsretracted position, and between its retracted and extended positions,respectively.

FIGS. 20, 21, and 22 are diagrammatic elevation views, taken through alatch bolt mechanism of the door and the final closing mechanism on thedoor frame showing the relationship of the latch bolt member and strikerpin to the weather strip on the vehicle body during various respectivestages of door closing.

FIG. 23 is a schematic circuit diagram of an electrical system that maybe employed in controlling the operation of the powered sliding dooroperating system.

FIG. 24 is a schematic circuit diagram of an electrical door reversingapparatus for causing the closing door to stop and reverse to an openingmovement when the apparatus detects the presence of an obstruction.

FIG. 25 is a typical plot of drive motor current versus time during adoor closing operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 through 25 show one preferred embodiment of the presentinvention, as applied to a powered door operating system for a vehiclesliding door, for purposes of illustration only. One skilled in the artwill readily recognize from the following discussion that the principlesof the present invention are equally applicable to powered dooroperating systems for applications other than the vehicular applicationillustrated in the drawings, as well as to non-door or non-vehicularcable-actuated devices having one or more actuating cables.

In FIGS. 1 through 8, a van type of vehicle 10 is illustrated, and apowered door operator and door operating system according to theinvention is used to open and close a sliding door 12. The sliding door12 is supported on the body of the van 10 at three points. The firstpoint of support includes a forward upper bracket and roller assemblyshown generally at reference numeral 14 (FIGS. 2 and 8), which in turnincludes an arm 15 one end of which is fastened to the upper forward endof door 12, and the other end of which carries one or more rollers 16 onits upper surface. A number of rollers 16 engage and ride in a curvedupper forward guide rail or guide member 17 is fixedly carried on thelower surface of a vehicle body member 18, which surrounds a dooropening 19 formed in a side wall 20 of the van 10.

The second point of attachment comprises a forward lower bracket androller assembly, shown generally at reference numeral 21, which includesan arm 22 having one end fixedly attached to the lower forward end ofthe door 12 and one or more rollers 23 carried at the other end. Therollers 23 engage and ride in a curved lower forward guide rail or guidemember 24 attached to a vehicle body member 25, which surrounds thelower portion of the door opening 19.

The third point of attachment includes a rear mid-level, bracket androller assembly shown generally at reference numeral 26, which includesan arm 27 (FIG. 7), with one end of the arm 27 being fixedly attached tothe rear end of the door 12 pivotally attached at the other end 28 toone end of a link 29. The other end of the link 29 carries a pluralityof rollers 30. The rollers 30 engage and ride in a curved rear guiderail or member 31 that is carried on the outside of the side wall 20, atan intermediate level, approximately midway between the levels of theupper and lower guide rails 17 and 24, respectively. The guide members17, 24, and 31 curve adjacent their forward ends toward the inside ofthe van 10.

The above-discussed three points of support allow the slide door 12 tobe slidably moved forwardly and rearwardly along the guide members 17,24, and 31, with the door 12 being guided by the guide members 17, 24,and 31, through initial closing and final opening movements that aregenerally parallel to the side wall 20 of the van 10, as shown in FIG.3, and through final closing and initial opening movements that aregenerally toward and generally away, respectively, from the plane of thedoor opening 14, as shown in FIGS. 4 and 5.

Referring to FIG. 3, when the door 12 is opened fully to the left, orrear, relative to the guide members 17 24, and 31 the rollers 16, 23,and 30 are at the rear ends of their respective guide members 17, 24,and 31. When the door 12 is then moved to the right, or forward, itsinitial closing movement relative to the side wall 20 is essentiallyparallel to the side wall 20 for most of its traversing movement towardsthe door opening 19. As the door approaches the right hand ends of thevarious guide members 17, 24, and 31 the curved portions of the guidemembers 17 and 24 are initially encountered by the corresponding rollers16 and 23 so that the forward end of the door 12 moves inwardly towardthe door opening 19 before the rear end of the door 12 starts movinginwardly. Thus, the forward end of the door 12 engages the weather stripin the door frame before the rear end of the door 12, causing a pivotingaction, as may be seen by comparing FIG. 4 with FIG. 5. As the rollers30 of the rear bracket and roller assembly 26 move through theinwardly-curved, forward end portion of the guide member 31, the finalclosing movement of the door 12 is accompanied by movement of the rearportion of the door into the door opening 19, as shown in FIG. 5.

In FIGS. 6 through 13, a powered door operator or drive assembly 235 isshown and moves the sliding door 12 through its initial and finalopening and closing movements. The door operator 235 includes a cablespool drive motor 202M interconnected with a mounting bracket 244, whichis attached to the inside of the side wall 20 by way of one or moremounting tabs 36. When selectively energized, the motor 202M drivingrotates a drive pulley or cable spool 238, through a clutch mechanism(not shown) coupled to the motor's gearing and output shaft (not shown).When the clutch mechanism is de-energized, or in an electrical systemfailure, the motor 202M and its associated gearing are disengaged fromthe cable spool 238, thus allowing manual operation of the door 12.Optionally an unclutched, high efficiency, back-driveable spur geardrive mechanism (not shown) may be employed with the motor 202M torotate the cable spool 238, while still allowing for manual operation ofthe door.

A lower flexible sheath or conduit 40 extends from a clamp 249 adjacentthe cable spool 238 to a clamp member 149 attached to the lower portionof the inside wall 45 of the van 10, generally adjacent the forward endof the wheel well, and securely retains the forward end of the flexiblesheath 40. The sheath 40 protects and guides a lower cable member 41extending around the wheel well between the cable spool 238 and an idlerpulley 152. One end of the cable member 41 is anchored on the cablespool 238, as shown in FIGS. 10 through 12, preferably by way of anenlarged cable retainer member 321 which is received and anchored in anopening 313 formed in a flange 311 of the cable spool 238. The opening313 communicates with a series of helical grooves 316 and 312, by way ofa slot 314 which allows the cable 41 to be wound onto a groove portion312. The other end of cable member 41 passes around an idler pulley 152,and then proceeds through the lower guide member 24, over a wear strip46 in the guide member 24, to an anchor point (not shown) on the forwardlower bracket or arm 22 of the door 12, generally adjacent to roller 23.

An upper flexible sheath or conduit 43 extends from the clamp 249adjacent the cable spool 238 to a clamp 148 attached to a mid-levellocation on the inside wall 45 of the van 10, generally adjacent therear edge of door 12, at a vertical height generally corresponding tothe height of the rear guide member 31. The clamp 148 securely holds theforward end of flexible sheath 43 to the wall 45 and protects and guidesan upper cable member 42 as the cable member extends along the insidewall of the van 10, between the cable spool 238 and an idler pulley 48about which it extends. One end (not shown) of the cable member 42 isanchored on the cable spool 238 in the same manner as described above inconnection with the cable member 41. The cable member 42 then passesthrough the sheath 43, around the idler pulley 48, over a wear strip 47at the forward end of the rear guide member 31, and along the rear guidemember 31 (FIG. 7), through a grommeted opening 49 in the link 29 of therear bracket and roller assembly 26, with its other end anchored on thelink 29 by a number screw clamps 7, 8, and 9, for example.

As shown primarily in FIGS. 10 through 12, the cable spool 238 has anopen, generally channel-shaped opening or groove, indicated by referencenumerals 312 and 316, formed along a generally helical path on its outercircumferential edge. In contrast to the circular, or non-helical,groove configuration found on conventional drive pulleys, such as thatshown in the above-mentioned U.S. Pat. No. 4,862,640, the helical grooveconfiguration of the cable spool 238 avoids the "wrap-up" or "stacking"of the cables 41 and 42 within such a non-helical pulley slot, whichundesirably results in an effective wrap radius that varies withrotation of the drive pulley in a manner that causes one of the cables41 or 42 to be taken up, or paid out, at a rate that is inconsistentwith the pay-out or take-up rate of the other cable at many, if not all,stages of powered door operation. These effects thus necessitated theinclusion of a spring-loaded drive pulley tensioning mechanism in thesystem of such above-mentioned patent in order to take up cable slack soas to maintain the required cable tension and compensate for differencesin the travel or movement of the cables 41 and 42.

Thus, in order to avoid the above effects, the cable spool 238 includesthe helical groove configuration discussed above and illustratedprimarily in FIGS. 10 through 12. In addition, these effects are avoidedin the illustrated exemplary embodiment and application of the presentinvention by the provision of a varying radial groove depth (resultingin a varying groove radius) along at least a portion of the helicalgroove path In this exemplary embodiment, the radial depth of the grooveportion 312 increases from left to right, as viewed in FIGS. 10 through12, in order to vary the take-up rate, or the pay-out rate, of at leasta portion of at least one of the cables 41 and 42, with respect to therotation of the cable spool 238, as the cable spool 238 is rotated inrespective opposite directions. The groove portion 316, however, has agenerally constant radial depth, with the pay-out rate, or the take-uprate of the cables 41 and 42 correspondingly remaining generallyconstant with respect to rotation of the cable spool 238.

Thus, in the exemplary embodiment illustrated in the drawings, therequired compensation for differences in speed or travel rates betweenthe cables 41 and 42 at various stages of powered door operation isaccomplished by way of the varying radial depth of the groove portion312 and the generally constant radial depth of the groove portion 316.The relationship caused by such a configuration is illustrated in FIG.13, wherein the groove radius for the cable spool 238 is plotted againstangular rotational position. The portion 330 of the plot in FIG. 13represents a constant radius part of the groove portion 316 for thelower cable 41, and corresponds to the open position of the door 12. Theportion 331 of the curve represents a variable radius part of the grooveportion 312 for the upper cable 42, and corresponds to a portion of theclosing movement of the door 12, with the portion 332 of the curvecorresponding to a constant radius portion of the groove for the uppercable 42 at the fully closed position of the door 12. The portion 333 ofthe curve corresponds to a generally linear transition between theportion of the helical groove for the upper cable 42 and the portion forthe lower cable 41, and the portion 334 represents a constant radiusportion of the groove for the lower cable 41.

The relationship of FIG. 13, showing the cable travel in the exemplaryembodiment depicted in the drawings was derived empirically by measuringthe position of the door 12 and each of the drive cables 41 and 42 atvarious stages of the door operation, moving the door in very smallincrements for each measurement. The empirical data was then fitted to asixth-order polynomial equation and appropriate derivatives were takento determine cable travel speed and acceleration equations in order todetermine the proper parameters to be used in programmingnumerically-controlled machining equipment. As a result, therelationships depicted in FIG. 13 are only exemplary, and are shown forpurposes of illustration only. One skilled in the art will now readilyrecognize that other similarly ascertainable relationships will berequired for other powered door applications, or for othercable-actuated devices. It will be appreciated, though, that theprinciples of the present invention are also applicable to cable spoolshaving one or more drive cables, to those having a variable radius(variable radial depth) helical groove along all, or a part of, thehelical path, to those having variable-depth and constant-depth grooveportions that are either continuous or discontinuous with one another,or to those that either extend in the same or opposite directions,and/or to those driven at either constant or variable speeds. Oneskilled in the art will also readily recognize that the cables 41 and 42can be separate and distinct, each with its own cable retentionarrangement on the cable spool 238, as described above, or that thecables 41 and 42 can optionally be continuous with one another, with aportion of the continuous cable being anchored to the cable spool in anyof a number of ways known or readily ascertainable in the art.

Finally, the exemplary cable spool 238 in the drive arrangement orassembly 235 also includes a number of mounting holes 315, for securingthe cable spool 238 to a drive hub or other such drive member (notshown) on the above-described motor-and-clutch mechanism, which isreceived within the drive member mounting opening 322 shown in FIG. 12Also, the assembly 235 includes a power supply cable 336 and,preferably, a control cabinet or housing structure 237, as shown in FIG.9.

As best seen in FIG. 6, the idler pulley 152 is fastened to the lowerportion of the inside wall 45 of the van 10, generally adjacent the rearof lower guide member 24 (at the inner rocker panel) by a bolt 153. Thebolt 153 also acts as the rotational axis and attachment point for anidler pulley 139, about which an electrical cord or cable 136 extendsfrom a spring reel 137 and an idler roll 138 to the interior of the door12. The electrical cable 136 passes through the lower guide member 24 toa clamp 154 on bracket 22 and then into the interior of the door 12 byway of an aperture 155. The electrical cable 136, whose function isdescribed in more detail below, winds and unwinds from the reel 137concurrently with the opening and closing movements of the door 12.

As the door 12 moves generally parallel to the vehicle body duringclosing, a guide pin 61 (FIG. 2) at the forward end of the door 12 movesinto a conical recess (not shown) in a body member 59, which forms aforward end of the door opening 19. Referring to FIGS. 4 and 5, as thepin 61 engages the conical recess in the door frame 59, the rear of thedoor 12 begins a generally inward movement, and the motion of the door12 becomes complex so that the lower cable member 41 does not pay outfrom the cable spool 238 at the same rate as does the upper cable member42 being wound onto the cable spool 238 which accommodates orcompensates for the different cable travels during final closingmovement of the door, as is discussed above.

Referring to FIG. 6, with the door 12 in the closed position, the arm 22of forward lower bracket and roller assembly 21 is positioned at itsmost forward and inward position on the lower guide member 24. The lowercable member 41 thus contacts the guide member 24 and, as the motor 202Mand the cable spool 238 begin to open the door, the cable member 41pulls the arm 22 rearwardly, and the lower cable member 41 rubs againstthe lower guide member 24. Accordingly, the outer face or contact areaof the guide member 24 is covered with a friction-reducing wear strip 46composed of a low-friction, highly wear-resistant material to preventwear of both the cable member 41 and the guide member 24. Once the dooris approximately one-quarter of the way open, however, the cable 41moves freely within, but out of contact with, the lower guide member 24,from the arm 22 of the lower bracket and roller assembly 21 to the idlerpulley 152. The cable is then smoothly guided by the flexible lowersheath or conduit 40 to the cable spool 238, where it is actively woundor unwound by the motor 202M. Friction wear of the lower cable member 41is less during door closing than during door opening, because the cablemember 41 is rather passively unwound from the drive pulley 38 as thedoor is moved forward (toward its closed position) by the upper cablemember 42.

As best seen in FIG. 8, and in contrast with the lower cable member 41,the upper cable member 42 contacts the forward portion of the guidemember 31 during the full range of opening and closing movement of door12. During door closing, the upper cable member 42 is actively woundonto the cable spool 238 by the motor 202M and conversely, during dooropening, the cable member 42 is rather passively unwound from the cablespool 238. However, because of the above-mentioned contact with theguide member 31 during both opening and closing, a friction-reducingwear strip 47, similar to the wear strip 46, is provided on the outerface of the rear guide member 31.

It should be noted the upper cable member 42 moves around the guidemember 31, toward the pulley 48, located generally inward of the dooropening 19, and carries the bracket and roller assembly 26 and the rearend of door 12 along with it. Consequently, during the final closingmovement of door 12, the upper cable member 42 imparts a generallyinwardly-directed, low momentum closing force to the door 12. The inwardmovement of the rear end of the door 12, in turn, is accompanied by anengagement and latching of the latch bolt member 60 on the door 12(FIGS. 2 and 20), with the striker pin 105 on the vehicle body member45. Such latching engagement occurs just prior to final closing orclamping of the door 12 against the weather strip on the door frame, andis further described below. It should also be noted that when motor 202Mis de-energized, and when the latch bolt member 60 and the striker pin105 are not in latched engagement, the door 12 may be freely movedmanually between its nearly closed position and its fully open position.This is because the motor 202M and the cable members 41 and 42 addlittle frictional resistance opposing such manual movement, and becauseno provision is made to lock the cable spool 238 when the motor isde-energized.

As is perhaps most clearly shown in FIGS. 2, 8, and 14, the door 12 isprovided with respective inner and outer handles 50 and 51, which arelocated in respective recesses 62 and 63 in the door 12. When thehandles 50 and 51 are pulled to the rear (to the right as viewed in FIG.8), they move a pull rod 71 upwardly, a pivot plate 70 in a clockwisedirection, and a pull rod 57 forwardly. The forward movement of the pullrod 57 can also be initiated by an electrical solenoid SOL, the armatureof which is connected to the forward end of a pull rod 52. A link 53,which is pivoted to the door 12 at 54, and to the rod 57 at pivot 56, isrotated about its pivot 54 when the pull rod 52 moves forward uponactuation of the solenoid SOL. The forward movement of the pull rod 52causes the pull rod 57 to also move forwardly, due to the pivotconnection 56 between the pull rod 57 and the link 53. The pull rod 57,in turn, is connected to the latch bolt mechanism of the door 12, as isshown generally at reference numeral 60 in FIG. 2. Accordingly, wheneither of the handles 50 and 51 is pulled to the rear, or when thesolenoid SOL is energized, the pull rod 57 is moved to the left asviewed in FIG. 8, causing the latch bolt mechanism 60 to becomeunlatched, as is explained in greater detail below, and allowing thedoor to be either manually or automatically opened.

The movement of the pull rod 57 to its forward or unlatching position issensed by a limit switch 5LS, which is actuated by contact with the link53, and the limit switch 5LS in turn provides a signal to the electricalcircuits indicating that the door handles 50 or 51 have been manually orelectrically opened. The opening movement of the door handles 50 or 51also opens a forward latch member 58, which engages a suitable latchreceiving member (not shown) in the vehicle body member 59, generally atthe forward end of the door opening 19.

As will be discussed in greater detail below the push buttons 1PB, 2PB,3PB, and 4PB (FIGS. 1 and 14) are employed in initiating movement of thedoor 12 from its various positions. The push buttons 1PB and 2PB (FIG.14) are positioned in the door recesses 62 and 63, respectively, and areemployed in signalling the electrical circuits, from the location ofdoor 12, to move the door from its open position to its nearly closedposition. The push buttons 3PB and 4PB (FIG. 1) are positioned adjacentto the vehicle driver's seat to open and close, respectively, the door12.

Various positions of door 12 relative to the door opening 19 are sensedby limit switches that are mechanically carried on upper forward guidemember 17 and are electrically connected into the electrical controlcircuits of the door operating system. Thus, referring to FIG. 8, alimit switch 6LS is carried at the rear end of guide member 17 and isactuated when the door is at its fully open position, and a limit switch3LS is carried at an intermediate position, near the forward end of theguide member 17, and is actuated when the door 12 reaches anintermediate position, about two inches from its nearly closed position.The arrival of the door at its nearly closed position is sensed by alimit switch 4LS (FIGS. 20 and 21), which is actuated when the latchbolt member 60 latches onto the striker pin 105. Referring to FIGS. 15Aand 15B, the limit switch 3LS is mounted outboard of the guide member 17and is preferably provided with a curved, rockable or pivotable actuatorarm 75 that extends through a slot 76 in an outer wall 77 to theinterior of the guide member 17. The actuator arm 75 is contacted andactuated by the roller 16 of the upper forward bracket 15 of the door 12when the roller 16 passes over the arm 75. Thus any outwardly-directedforces exerted by the roller 16 as it passes by limit switch 3LS aretaken up by the portion of the outer wall 77 surrounding the slot 76 inthe guide member, while actuator arm 75 moves within the slot 76 andactuates and deactuates the limit switch 3LS as the roller 16 passes byduring the opening and closing movements of the door 12.

Referring now to FIGS. 2, 8, and 16 through 22, one version of a finalclosing device or clamping mechanism, shown generally at referencenumeral 80, is provided for moving the door 12 from its nearly closedposition, at which the latch bolt member 60 latches onto the striker pin105, to a fully closed position, at which the weather strip of the door12 is compressed, and the door is fully closed, flush with the side wall20. The final closing device 80 includes a motor 1M having an outputshaft 81, on which an enlarged shaft extension or striker shaft 82 ismounted and keyed for rotation therewith. The striker shaft 82 ismachined adjacent one end of its outer surface to provide a ratchettooth 83 having a radially extending face 84. The radially inner andouter ends of the face 84 are connected by a smooth spiral cam surface85.

The forward end of the outer surface of the striker shaft 82 also has agroove 86 machined therein so that a protruding cam surface 87 isprovided relative to groove 86 at the outer surface of the striker shaft82. The striker shaft 82 rotates within a bushing 88 that is press fitinto an outer housing 89, and a thrust washer 90 seats against the rearend (right-hand end as viewed in FIG. 16) of the bushing 88 in a steppedrecess 89a of the housing 89. The washer 90 separates the end of thebushing from a collar or shoulder 91 formed at the rear end (right-handend as viewed in FIG. 13) of the striker shaft 82.

A bracket plate 92 joins the motor 1M to the housing 89 and includes anopening 93, through which the collar 91 freely passes so that thestriker shaft 82 abuts against a shoulder 94 on the motor shaft 81. Thebracket 92 includes a plurality of small bolt holes 95, which align withcorresponding threaded holes (not shown) on the back surface of thehousing 89 to allow the bracket 92 to be rigidly fastened to the rearend of the housing 89 by bolts (not shown). Similarly, the bracket 92 isprovided with a plurality of large bolt holes 96, which are in alignmentwith corresponding threaded bolt holes 97 at the forward end of themotor 1M. Bolts or other suitable fasteners (not shown) are employed tofasten the motor 1M to the opposite side of the bracket 92 from thehousing 89 so that the various parts of the final closing device 80 arefirmly interconnected.

A pair of limit switches 1LS and 2LS threadedly engage correspondingthreaded openings 98 and 99 in the housing 89. The openings 98 and 99are aligned with corresponding openings 98a and 99a in the bushing 88 sothat the actuators 100 and 101 of the respective limit switches 1LS and2LS ride in the groove 86 of the striker shaft 82 and are actuated bythe protruding cam surface 87 during rotation of the striker shaft 82,as will be explained in greater detail below.

A pawl 102, a spring 103 and a lockbolt 104 are carried in an aperture104a in the housing 89. The aperture 104a is aligned with an aperture104b in the bushing 88 so that the pawl 102 is spring loaded downwardlyinto engagement with the spiral cam surface 85 on the outer surface ofthe striker shaft 82. During clockwise rotation of striker shaft 82 (asviewed in FIG. 16), the pawl 102 rides up the spiral cam surface 85until it reaches the top of the tooth 83 and then drops down intoengagement with the radial face 84 of the tooth 83. This engagementrepresents the fully closed or clamping position of the final closingdevice 80, which is shown in FIG. 18, and coincides with the actuationof the limit switch 2LS by cam 87. The unclamped or open position of thefinal closing device 80 is illustrated in FIG. 17 and coincides with theactuation of the limit switch 1LS by the cam 87.

The final closing device 80 is provided with a striker pin 105, whichprojects axially outwardly from an end surface 106 of the striker shaft82. The end surface 106 constitutes a striker plate on which the strikerpin 105 is eccentrically supported relative to the rotary axis of theshaft extension 82. The end of the striker pin 105 remote from thesurface 106 is provided with a flange or enlarged head portion 107 forcrashworthiness purposes. Preferably, the flange 107 is capable ofpreventing the latch bolt mechanism 60 on the door 12 from axiallypulling free of the striker pin 105 during high impact axial loads.

The end of the housing 89 remote from the motor 1M is provided with areduced diameter threaded end portion 108, which is threadedly engagedby mounting nut 109. The end portion 108 is passed through one side of acorresponding opening in the rear body member 45 of the door opening andis bolted thereto by tightly threading the mounting nut 109 onto the endportion 108 from the other side of the body member. A key and slotarrangement (not shown) may optionally be provided to insure that theclamping mechanism housing 89 does not rotate relative to the framemember 45.

Referring to FIGS. 17 through 19, the various components 82 through 85,and 102 through 104, cooperate to form a unidirectional lock, showngenerally at reference numeral 110. The unidirectional lock 110 servesto prevent reverse rotation or back-driving of the striker pin 105 inthe event that the fully closed door is impacted from the inside underhigh loads. As shown in FIG. 17, the striker pin 105 is extended to itsfully open or unclamped position, awaiting both the arrival of the latchbolt mechanism 60 (FIG. 8) and the movement of the latch bolt mechanism60 to its latched condition, prior to undergoing rotary motion, whichretracts the striker pin 105 and moves the door to its fully closed,clamped position. This extended condition of striker pin 105 is alsorepresented in FIGS. 20 and 21, with the latch bolt mechanism 60 shownin its unlatched condition prior to engagement with the striker pin 105in FIG. 20, and with the latch bolt mechanism 60 shown in its latchedcondition in full engagement with the striker pin 105 in FIG. 21. Whenthe latch bolt mechanism 60 fully engages and latches onto the strikerpin 105, it actuates a limit switch 4LS, which signals the electricalcontrol system that the latch bolt mechanism 60 is fully latched. Inturn, the electrical circuits then cause the motor 1M to drive thestriker pin 105 from its extended position (shown in dashed lines inFIG. 22), to its retracted position (shown in solid lines in FIG. 22).This movement is occasioned by movement of the door 12 to its fullyclosed position, in which the door compresses the weather strip 115against the vehicle body members constituting the frame of the dooropening 19. Such movement is also occasioned by clockwise rotation ofthe striker shaft 82 from the position shown in FIG. 17 to the positionshown in FIG. 18, at which the pawl 102 has dropped into place behindthe ratchet tooth 83 and is abutted by the face 84 of the ratchet tooth53.

If the fully closed door 12 is impacted from the inside under a highload, such as during a vehicle crash, the unidirectional lock 110 willresist reverse rotation or back driving of the striker pin 105 toprevent accidental, unintended opening of the door. This occurs as aresult of the pawl 102 being in a face-to-face confronting engagementwith the face 84 of ratchet wheel tooth 83.

As shown in FIG. 19, the striker pin 105 is moved from its retractedposition to its extended position by clockwise rotation of the shaft 82.This rotation is initiated by the electrical circuits of the powereddoor operating system after a door opening cycle has been initiated bythe operator and the latch bolt mechanism 60 has cleared the striker pin105, as will be discussed in greater detail below.

Referring now to FIG. 23, which illustrates a circuit diagram of theelectrical control system for controlling the normal operation of thepowered sliding door operating system, with the electrical circuitry ofthe door reversing apparatus of the present invention beingschematically illustrated separately in FIG. 24 and discussed in moredetail below. In FIG. 23, a line numbering system has been employed tofacilitate the description of the electrical system, with the linenumbers being listed on the left side of FIG. 23 and runningconsecutively from line No. 101 through line No. 119. The line numberson which the contacts of relays appear have been listed to the right ofthe relays that control them, and normally closed contacts are indicatedby underlining in the listings. Thus referring to FIG. 23, relay 3CR(line 103) is provided with two sets of contacts, a normally-open set ofcontacts in line 114 and a normally-closed set of contacts in line 115.

Twelve volt DC voltage is supplied from the automobile battery (notshown) to the electrical control system of the powered sliding dooroperating system by way of a fuse F1 and a conductor 130. Twelve volt DCvoltage is also supplied to the electrical control system through atransmission lever switch (not shown) via a fuse F2 and a conductor 131.The conductor 131 is energized only when the transmission lever is ineither the park or neutral position. A conductor 132 is connected to thegrounded side of the battery to complete the circuit across theelectrical control system.

TABLE I below lists and describes the functions of the various pushbuttons, limit switches, solenoids, and motors used in the electricalcontrol system circuits for controlling the powered sliding dooroperating system.

                  TABLE I                                                         ______________________________________                                        DESCRIPTION OF COMPONENTS                                                     Components                                                                             Description                                                          ______________________________________                                        1LS      Normally closed; opens when striker pin rotates                               to fully extended (unclamped) position.                              2LS      Normally closed; open when striker pin rotates                                into its retracted (clamped) position.                               3LS      Open when the door is forward of its                                          intermediate position, and closed when the door                               is rearward of its intermediate position.                            4LS      Normally closed; opens when latch member moves                                to fully closed (latched) position.                                  5LS      Normally open; closes when door handle is pulled                              open or when solenoid SOL is energized.                              6LS      Normally closed; opens when door reaches fully                                open position.                                                       1PB      Normally open; manually closed to close door                                  from outside of vehicle.                                             2PB      Normally open; manually closed to close door                                  from inside rear of van.                                             3PB      Normally open; manually closed by operator of                                 vehicle to open door from the driver's station.                      4PB      Normally open; manually closed by operator to                                 close sliding door from the driver's station.                        SOL      A solenoid connected to the door opening                                      mechanism for unlatching the latch bolt                                       mechanism and holding the latch bolt mechanism                                open, while energized.                                               1M       Motor for moving the striker pin between its                                  extended and retracted position to move the door                              from its unclamped position to its clamped                                    position.                                                            202M     Motor for driving the cable spool and moving the                              door between its fully open and nearly closed                                 positions.                                                           ______________________________________                                    

Referring to FIG. 23 in conjunction with FIGS. 6 and 8, the electricalcircuits of the powered sliding door operating system are shown in thecondition they assume when the door is in its fully closed, fullyclamped condition. Starting from this condition, a full door opening,and then a full door closing, cycle will be considered.

With the door in the fully closed and clamped position the operatormanually actuates the door handle 50, closing the limit switch 5LS (line106), or presses the push button 3PB (line 105). Accordingly, a controlrelay 4CR (line 105) energizes closing its contacts in line 108 and acontrol relay 5CR (line 106) energizes, closing its contacts in line119. The closing of the contact 4CR in line 108 preconditions thecontrol relay 6CR for subsequent energization when control relay 2CRenergizes. The closing of the contacts 5CR in line 119 causes thesolenoid SOL to energize to mechanically hold the door handle 50 in theopen position, retaining the limit switch 5LS in its actuated conditionand retaining its contacts 5LS in line 106 closed. The opening of thedoor handle 50 and the energization of the solenoid SOL cause the latchbolt mechanism 60 to unlatch, which, in turn, causes the limit switch4LS (FIG. 20) to deactuate, closing its contacts 4LS in line 102. Itshould be noted that the unlatching of the latch bolt mechanism 60 freesthe door to move from its clamped position, or fully closed position, toits unclamped position, or nearly closed position, due both to theresulting expansion of the compressed weather seal strip and to the dooropening movement initiated by way of the motor 202M, as described below.

The closing of the contacts 4LS in line 102 causes the control relay 2CR(line 102) to energize, opening its contacts 2CR in line 104 and closingits contacts 2CR in lines 103 and 108. The closing of the contacts 2CRin line 103 and the opening of the contacts 2CR in line 104 are withoutfurther effect at this time. The closing of the contacts 2CR in line 108causes the control relay 6CR (line 108) to energize through thenow-closed contacts 4CR in line 108. Accordingly, the contacts 6CR inline 109 close, bypassing the contacts of the relay 4CR in line 108, thecontacts 6CR in line 110 open, without further effect at this time, andthe two sets of contacts 6CR in line 117 close, thus energizing themotor 202M (line 116) for driving the door 12 from its fully or nearlyclosed position toward its fully open position.

As the door 12 moves away from its nearly closed position to itsintermediate position, the limit switch 3LS actuates and its contacts3LS (line 101) close, energizing the relay 1CR (line 101). Accordingly,the contacts 1CR in line 103 close, energizing the control relay 3CR(line 103) through the now-closed contacts 2CR in line 103, the contacts1CR in line 104 open, without further effect at this time the contacts1CR in line 106 open, de-energizing the control relay 5CR (line 106),and the contacts 1CR in line 113 close, without further effect at thistime. The de-energization of the control relay 5CR (line 106) opens thecontacts 5CR in line 119, de-energizing the solenoid SOL (line 119).Accordingly, the door handle resumes its unpulled condition, and thecontacts 5LS (line 106) open, thus de-energizing the control relay 4CRwithout further effect (since the contacts 4CR in line 108 open, but arebypassed by the contacts 6CR in line 109).

This energization of the control relay 3CR (line 103), due to theclosing of the contacts 1CR in line 103 (while contacts 2CR in line 103were closed) causes the contacts 3CR in line 114 to close and thecontacts 3CR in line 115 to open. Accordingly, the motor 1M (line 114)becomes energized and starts rotating the striker pin 105 from itsretracted position toward its fully extended position. During therotation of the motor 1M, the limit switch contacts 2LS (line 104) closeas the striker pin starts rotating out of its retracted position, butthis action is without further effect since the relay 2CR is energizedand its contacts in line 104 are open. When the striker pin 105 rotatesto its fully extended (unclamped) position, the limit switch contacts1LS (line 103) open, de-energizing the control relay 3CR (line 103).With the de-energization of the control relay 3CR (line 103), itscontacts 3CR in line 114 open and its contacts 3CR in line 115 close.Accordingly, the input side of the motor 1M is de-energized andgrounded, braking the motor and stopping the movement of the striker pin105 in its extended (unclamped) position.

Then the door 12 eventually arrives at its fully open position, at whichthe time limit switch 6LS actuates, opening contacts 6LS in line 108 tode-energize the control relay 6CR (line 108). Accordingly, the two setsof normally open contacts 6CR in line 117 open, thus de-energizing themotor 202M, the normally open contacts 6CR in line 109 open withoutfurther effect, and the normally closed contacts 6CR in line 110 closewithout further effect, but preconditioning line 111 for subsequentclosing operations. Thus the door is now in its fully open condition,with the latch bolt mechanism 60 unlatched, and with the clampingmechanism 80 open, or unclamped, ready for a door closing cycle to beinitiated.

To initiate the portion of the door closing cycle that moves the door 12from its fully open position to its intermediate position, one oranother of the push buttons 1PB (line 110), 2PB (line 111) or 4PB (line112) is depressed. The push buttons 1PB and 2PB are physically locatedadjacent to the door handle 50, while the push button 4PB is controlledby the driver of the vehicle at the driver's location. When any one ofthe push buttons 1PB (line 110), 2PB (line 111), or 4PB (line 112) isdepressed, their corresponding contacts close, energizing the controlrelay 7CR (line 110). Accordingly, the contacts 7CR in line 113 close,locking the relay 7CR in an energized condition independently of thepush button contacts in lines 110, 111, and 112, since the contacts 1CRin line 113 are closed. In addition, the two sets of normally opencontacts 7CR in line 118 close with the energization of the relay 7CR toenergize the motor 202M with a polarity that causes the motor 202M todrive the cable spool and thus the door 12 in a closing direction, fromits fully open position toward its intermediate position.

The initial closing movement of the door 12 from its fully open positiontoward its intermediate position results in the limit switch 6LSdeactuating, causing its contacts 6LS in line 108 to close withoutfurther effect since the contacts 4CR and 6CR in lines 108 and 109,respectively, are open. The door 12 thus continues to move toward itsintermediate position and, upon arrival at the intermediate position,the limit switch 3LS (line 101) opens, de-energizing the control relay1CR (line 101), causing its contacts in line 103 and line 113 to open,and causing its contacts in line 104 and line 106 to close. The openingof the contacts 1CR in line 103 is without further effect because thecontacts of the limit switch 1LS in that line are already open. Theclosing of the contacts 1CR in line 104 is without further effectbecause the contacts of the relay 2CR in that line are open. The openingof the contacts 1CR in line 106 is without further effect since the pushbutton 3PB (line 105), the limit switch 5LS (line 106), and the limitswitch 7LS (line 107) are all open. The opening of the contacts 1CR inline 113 de-energizes the control relay 7CR (line 110) and opens itscontacts 7CR in line 113 without further effect, and further opens itstwo sets of contacts 7CR in line 118. The opening of the two sets ofcontacts 7CR in line 118 de energizes the motor 202M, stopping the door12 at the intermediate position.

Accordingly, the door 12 arrives at its intermediate position and theelectrical circuits assume a condition awaiting further closing signalsat that position. At this time, further closing movement of the door 12under the control of any of the push buttons 1PB, 2PB or 4PB requiresthe respective button to be maintained in its depressed condition inorder to continue moving the door 12 toward its fully closed position.This is due to the fact that the control relay 1CR (line 101) isde-energized and its contacts 1CR in line 113 are open, thus preventingenergization of relay 7CR through any path other than through theclosing of the contacts 1PB (line 110), 2PB (line 111), or 4PB (line112).

Assuming that one of the push buttons 1PB, 2PB, or 4PB is depressed tocontinue the closing movement of the door 12 from its intermediateposition towards its nearly closed position, the control relay 7CR (line110) energizes and, in turn, energizes the motor 202M by way of its twosets of contacts 7CR in line 118. Accordingly, while the selected pushbutton 1PB, 2PB, or 4PB is being depressed, the door 12 continues tomove toward its nearly closed position. The continued movement of thedoor 12 causes the latch bolt mechanism 60 to engage and then to latchonto the extended striker pin 105 of the clamping mechanism 80.Accordingly, the limit switch 4LS (line 102) actuates, opening itscontacts in line 102 and de-energizing the control relay 2CR (line 102).As a result of this, the contacts 2CR in line 103 close without furthereffect, and the contacts 2CR in line 108 open, thus de-energizing therelay 7CR (line 110). Accordingly, the two sets of contacts 7CR in line118 open, stopping the motor 202M, with the door 12 located between itsnearly closed and fully closed positions. In addition, suchde-energization of the control relay 2CR (line 102) causes its contacts2CR in line 104 to close, energizing the control relay 3CR (line 103)through the now-closed contacts 1CR and 2LS in line 104. Theenergization of the control relay 3CR (line 103) causes its normallyopen contacts in line 114 to close and its normally closed contacts inline 115 to open. Accordingly, the motor 1M becomes energized and startsdriving the striker pin 105 of the clamping mechanism 80 from itsextended position to its retracted position thereby moving the door 12from its unclamped condition to its fully clamped position.

The initial movement of the striker pin 105 from its extended positiontoward its retracted position causes the contacts of the limit switch1LS in line 103 to close without further effect, because the contacts1CR in line 103 are open at this time. When the striker pin 105 reachesits fully retracted position, and the door 12 is in its fully clampedcondition, the limit switch contacts 2LS of line 104 open, de-energizingthe control relay 3CR (line 103). Accordingly, the contacts 3CR of line114 open, and the contacts 3CR of line 115 close, thus grounding theinput to the motor 1M of line 114 and causing the motor 1M to brake to astop, with the striker pin 105 in its fully retracted position, and thedoor 12 fully clamped. At this point, the door 12 is fully closed, andthe electrical circuits are back to the initial condition describedabove.

In FIG. 24, a schematic circuit diagram for an exemplary embodiment of areversing apparatus according to the present invention is shown withexemplary component values, for purposes of illustration only. Oneskilled in the art will readily recognize that the principles of thepresent reversing apparatus invention are equally applicable tocircuitry other than the particular circuitry illustrated in FIG. 24, aswell as to power actuator devices other than that of the exemplaryvehicle door application shown in the drawings and discussed herein.

In FIG. 24, an exemplary reversing apparatus circuit 401 includes aresistor 402, which can be a 0.05 ohm resistor for the 12 volt DC powersupply in the vehicle door operator system described above, for example.The resistor 402 is wired between the ground and one side of theabove-mentioned drive motor 202M in such a way as to be in series withthe drive motor 202M during door closing. A level shifting stage 403 ofthe circuit 401, which preferably includes a pair of operationalamplifiers 404 and 405, reads the voltage across the resistor 402, as arepresentative measurement of instantaneous motor current. The levelshifting stage 403 converts this voltage to an instantaneous voltagethat is proportional, and representative of, the instantaneous currentdraw of the motor 202M in a voltage range convenient and appropriate tothe other components of the circuit 401. An operational amplifier 406,along with its associated equally-sized resistors 407 and 408 and acapacitor 409, provides an amplified signal at approximately one-half ofthe power supply voltage to the level shifting stage 403, which in turnprovides the above-mentioned instantaneous, representative voltage to apreferred solid state relay switch 410.

When the obstruction-caused reversing function is not indicated orneeded, the relay switch 410 is set to feed an adjustable, steadyby-pass voltage to a pair of operational amplifiers 412 and 413, withthis by-pass voltage being supplied from an adjustable preselectedpotentiometer 411, and being representative of, but slightly higherthan, that voltage corresponding to the normal motor current.

A timer delay circuit 414, which includes an operational amplifier 415,a capacitor 416, and a potentiometer 417, is energized by receiving asignal indicating that the door 12 has begun to close, such as a signalfrom the above-discussed door-closing push buttons 1PB, 2PB, or 4PB.After a delay of approximately 0.75 seconds which allows the door topass through any detent in its mechanism, the capacitor 416 has becomecharged to a level higher than the adjustable voltage provided throughthe potentiometer 417, and the output of the operational amplifier 415switches (is drawn high). This switching causes the relay switch 410 tobe energized and switched to provide the instantaneous signalrepresentative of instantaneous motor current to the above-mentionedoperational amplifiers 412 and 413. By way of an R-C circuit 418,another delay of approximately 0.25 seconds is provided in order toallow for signal stabilization, and another preferably solid state relayswitch 421 allows the correct reference voltage to be delivered to oneinput of a comparator amplifier 420, as opposed to a reference voltageessentially at DC power supply which precludes the output of comparator420 from switching.

The amplifier 412 delivers a voltage representative of the motor currentaveraged over a preceding, predetermined short time interval, such as0.5 second, for example, to one input of a difference amplifier 419.Similarly, amplifier 413 delivers the instantaneous voltage, which isrepresentative of the instantaneous motor current (averaged over thepreceding 15 milliseconds for noise reduction) to the other input of thedifference amplifier 419.

The difference amplifier 419 then delivers a difference voltage to theother input of the comparator amplifier 420, with such differencevoltage being representative of the motor current difference between thepresent instantaneous motor current (from amplifier 413) and the motorcurrent averaged over the preceding 0.5 second (from amplifier 412). Ifthis difference voltage rises to a level above the reference voltagefrom a potentiometer 422, an obstruction is indicated, and therelay-reversing circuit 423 is actuated to send a signal to the controlcircuit shown in FIG. 23 in order to stop and reverse the drive motor202M.

FIG. 25 is a plot of motor current versus time during a closing cycle ofthe door 12, illustrating the effects on current draw caused by thevarious above-mentioned motions that the door 12 undergoes duringclosing.

In response to the signal to initiate the door closing cycle, the motor202M is energized, and the current draw rises in order to allow the door12 to initially move and to overcome a detent that serves to hold thedoor open, as illustrated by curve portion 436. Once this initial detentand inertia resistance is overcome, the door 12 is moved through therelatively low resistance portion of its movement, generally parallel tothe side of the vehicle, as indicated by curve portions 437, 438, and439 for respective vehicle orientations of a 15% uphill grade, a levelgrade, and a 15% downhill grade for example. Finally, during theabove-discussed inward door movement and latching operations, the motorcurrent rises to meet these high-resistance needs and then falls at thecompletion of the door closing, as indicated by the curve portion 440.Thus, as is discussed above, and as is readily shown in FIG. 25, thedrive motor 202M undergoes wide variations in current draw during anormal door closing cycle.

When an obstruction is encountered, however, as is indicated forpurposes of example by curve portions 443, 444, or 445, for therespective orientations discussed above the motor currentcorrespondingly rises. Thus, as is discussed above in connection withFIG. 24, the reversing apparatus of the present invention senses suchobstruction-caused current changes by circuit logic that effectivelycompares the instantaneous motor current with a time-averaged referencecurrent that "tracks" the normally varying motor current in order toaccurately detect the presence of a predetermined obstruction-causedresistance.

It will be appreciated by those skilled in the art, that in lieu of thehard-wired electronic circuitry shown in FIG. 24, and further explainedby FIG. 25, alternative electronic-based door closing control systemsmay be employed. For example, a microprocessor-based control system maybe substituted for the hard-wired electronic control system 401 shown inFIG. 24. In such a microprocessor based embodiment, the input signalfrom the current sense resistor 402 would be provided to ananalog-to-digital converter to convert the voltage across the resistorto a digital value proportional to the amplitude of such voltage. Theanalog-to-digital converter would provide this signal to amicroprocessor which would perform all of the level-shifting, timeintegrating and averaging, and comparison functions performed byoperational amplifier circuits 403, 406, 412-414, and 420. The softwareimplementation of the integration of a time-varying signal, thecomparison of digital values, and the shifting of a level of a signalare all well known to those skilled in the microprocessor art and neednot be described here. The output of the microprocessor in thisalternative embodiment would be used to drive a suitable power outputstage such as relay-reversing circuit 423 shown in FIG. 24.

Referring to FIGS. 6 and 8, and as indicated earlier herein, amulti-wire cable 136 may be employed if desired to interconnect theelectrical components inside the door 12 (e.g., the limit switches 4LSand 5LS, the push buttons 1PB and 2PB, and the solenoid SOL) with theremaining electrical components of the control system described below inconnection with FIG. 23 and with the reversing apparatus of FIG. 24. Thecable 136 exits from the forward lower portion of the door 12, by way ofan aperture 155, and is supported on the underside of the arm 22,adjacent to the roller 23 by a clamp 154. From the end of the arm 22,the cable 136 proceeds rearwardly along the lower forward guide member24, parallel to the lower cable member 40, and around the idlers 139 and138, to a spring driven take-up reel 137, on which it winds duringopening movement of the door and from which it unwinds during closingmovement of the door 12. An end portion 135 of the cable 136 exits fromthe upper surface of the take-up reel 137 in order to connect thevarious wires of the cable 136 to their corresponding lines of theelectrical control system of FIG. 23. The various control relays of theelectrical control system, and the wires associated therewith, arepreferably housed in one or more electrical cabinets, such as thecontrol cabinet or housing 237. The reel 137 is so dimensioned thatapproximately 3 turns of the reel 137 is sufficient to completely windand unwind the cable 136 during full opening and closing movements ofthe door 12. Thus the end portion 135 of the cable 136 is initiallyinstalled in an untwisted condition with the door 12 midway between itsfully open and fully closed positions so that it only twistsapproximately 1-1/2 turns in each direction during opening and closingof the door 12.

It should be pointed out that any of the embodiments of the presentinvention discussed herein can optionally be employed with or withoutthe inventions disclosed and described in the above-mentioned copendingpatent applications, entitled "VARYING RADIUS HELICAL CABLE SPOOL FORPOWERED VEHICLE DOOR SYSTEM", "CONTROL APPARATUS FOR POWERED VEHICLEDOOR SYSTEMS", and/or "POWERED CLOSING ASSIST MECHANISM FOR VEHICLEDOORS OR LID MEMBERS". Such inventions of such copending applicationscan optionally be used either alone or together, and either in additionto, or in substitution for, various components, sub-assemblies, orsub-systems described above, as well be readily apparent to one skilledin the art.

The illustrated exemplary applications of the present invention provideimproved control systems and circuitry for powered sliding door systemsfor automotive vehicles, such as vans, for example. The sliding door 12is moved with low momentum by the powered sliding door operator betweenits fully open position and its nearly closed position. In addition, thepowered sliding door operator system provides for the complete closingof the sliding door in a slow, controlled manner, and the effortrequired to manually open and close the sliding door is substantiallyreduced. Moreover, in the event that the powered sliding door operatoror system is not functional, due to a vehicle accident or a systemfailure or the like, the powered door operator and system of the presentinvention allows near-normal manual operation for opening and closingthe sliding door, even though such manual closing operation may requirea high momentum, "slamming" movement, as in conventional sliding doorclosing arrangements.

In addition, the present invention provides a reversing apparatus fordetecting the presence of an obstruction encountered by the movabledoor, or other movable member, and causing at least a stoppage, andpreferably a reversal, of its motion in order to substantially preventdamage to the obstruction, the door or other movable member, or the dooroperating system. Such reversing apparatus detects changes in drivemotor current during door closing that indicate the presence of anobstacle or obstruction by comparing signals representative ofinstantaneous motor current with a reference signal representative ofcurrent that is averaged over a predetermined short time interval. Thisfeature makes the reversing apparatus function independently of thenormally varying drive motor current, which results from the changes inthe types of movement of the door during closing as described above.

The foregoing discussion discloses and describes merely exemplaryembodiments of the present invention for purposes of illustration only.One skilled in the art will readily recognize from such discussion, andfrom the accompanying drawings and claims, that various changes,modifications and variations can be made therein without departing fromthe spirit and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. In a device having at least one movable memberdriven by an electric motor along a predetermined path, an apparatus fordetecting an obstruction in the travel path traversed by the member,said apparatus comprising:first means for monitoring an instantaneouselectric current provided to the electric motor to produce a firstanalog signal representative of the instantaneous amplitude of the motorcurrent; second means for monitoring an average electric currentprovided to the electric motor over a predetermined time interval toproduce a second analog signal representative of the average amplitudeof the motor current; and control means for producing a first controlsignal when the amplitude of said first signal exceeds the amplitude ofsaid second signal by a predetermined amount whereby said first controlsignal indicates that the movable member has encountered an obstructionin its path.
 2. An apparatus according to claim 1 furthercomprising:timing means, responsive to an initiation signal associatedwith a command to initiate movement of the movable member, forgenerating a first time-controlled signal after a first time delayperiod of a first predetermined length; and first time delay meansresponsive to said first time-controlled signal for blocking a path ofsaid first analog signal between said first means for monitoring andsaid control means during said first time delay period, and for passingsaid first analog signal after said first time delay period between saidfirst means for monitoring and said control means.
 3. An apparatusaccording to claim 2 wherein:said first predetermined time delay lengthcorresponds to a length of time required for the movable member to passa predetermined first area of a known increased resistance to themovement along the travel path prior to reaching a predetermined secondarea of a relatively uniform resistance.
 4. An apparatus according toclaim 3 further comprising:second time delay timing means for generatinga second time-controlled signal after a second time delay period of asecond predetermined length after said first time delay; and second timedelay for blocking said path of said first analog signal between saidfirst means for monitoring and said control means during said secondtime delay period, and for passing said first analog signal after saidsecond time delay period between said first means for monitoring andsaid control means.
 5. An apparatus according to claim 4, wherein saidfirst predetermined time delay length is less than about 0.8 seconds. 6.An apparatus according to claim 5, wherein said second predeterminedtime delay length is less than about 0.3 seconds.
 7. An apparatusaccording to claim 2, wherein said first means for monitoringincludes:means for converting the instantaneous electric currentprovided to the electric motor to a first voltage signal proportional tothe electric current; and level shifting means for producing a secondvoltage signal proportional to but different in amplitude from the firstvoltage signal.
 8. An apparatus according to claim 7, wherein said firstmeans for monitoring further includes:means for reducing transientconditions in said first analog signal representative of theinstantaneous amplitude of the motor current signal by averaging themotor current signal over a brief time period less than 25 milliseconds.9. An apparatus according to claim 1, wherein said control means forproducing a first control signal includes:first comparator means forreceiving said first and second analog signals and for producing a thirdanalog signal corresponding to a difference in values between said firstand second analog signals; means for producing a reference signalcorresponding to said predetermined amount; and second comparator meansfor producing said first control signal when the amplitude of said thirdanalog signal exceeds the amplitude of said reference signal.
 10. Anapparatus according to claim 1, further comprising:output means,responsive to said first control signal, for producing a change of statein a relay device when said first control signal is produced.
 11. In anautomatic powered door closing system driven by an electric motor, anelectronic system for sensing a predetermined increased resistance toclosing of a door, said electronic system comprising:first means formonitoring substantially instantaneous electric current provided to saidelectric motor, said first means including means for generating a firstsignal value changing in proportion with changes in said instantaneouselectric current; second means for generating a second signal valuecorresponding to an average of said first signal value over a shiftingspan of recent time less than about one second long; and output meansfor producing an output signal indicating that an obstruction has beenencountered by the door when the difference between said first signalvalue and said second signal value exceeds a predetermined limit.
 12. Anelectronic system according to claim 11, wherein said means formonitoring includes:level shifting means responsive to saidsubstantially instantaneous electric current for producing alevel-shifted signal proportional to, but different from, the amplitudeof said instantaneous current; means for producing a predetermined timedelay after a close door command; and means for inhibiting the deliveryof said first signal value to said output means during saidpredetermined time delay.
 13. An electronic system according to claim12, wherein said means for producing a predetermined time delay includesa potentiometer for adjusting the length of said predetermined timedelay within a predetermined range of values.
 14. An electronic systemaccording to claim 11, further comprising:means for producing areference signal proportional to the power supply voltage level, and forproviding said reference signal to said first means for monitoring, saidfirst means for monitoring including means for adjusting said firstsignal value produced thereby in order to compensate for fluctuations inthe power supply level.
 15. A door operator system for a door that isslidingly supported relative to a door opening in a panel of a vehiclebody, said door being supported adjacent a forward end on at least oneforward guide member and being supported adjacent a rear end on a rearguide member, said guide members guiding said door through an initialclosing movement and a final opening movement generally parallel to saidpanel, said guide members guiding said door through at least a portionof its initial opening movement generally away from the plane of saiddoor opening, and said guide members guiding said door through at leasta portion of its final closing movement generally toward the plane ofsaid door opening, said door operator comprising a first cable havingone end coupled to the rear end of said door and a second cable havingone end coupled to the forward end of said door for driving said dooralong said guide members to thereby move said door through said initialand final opening and closing movements, each of said cables beingsupported substantially entirely within the interior of the vehicle bodywhen the door is fully closed, said door operator system furtherincluding a rotatable cable spool and drive means including an electricmotor for selectively rotating said cable spool about an axis in eitherof two directions in order to actuate said first and second cables, saiddoor operator system further including an electronic reversing apparatusfor sensing a predetermined increased resistance to closing of said doorindicating the presence of an obstruction encountered by said closingdoor, said electronic reversing apparatus including: first means formonitoring substantially instantaneous electric current provided to saidelectric motor, said first means including means for generating a firstsignal value changing in proportion with changes in said instantaneouselectric current prior to said door encountering said obstruction;second means for generating a second signal value corresponding to anaverage of said first signal value over a shifting span of recent timeless than about one second long; and output means for producing anoutput signal indicating that said obstruction has been encountered bysaid door when the difference between said first signal value and saidsecond signal value exceeds a predetermined limit.
 16. The inventionaccording to claim 15, wherein said first means for monitoring includes:level shifting means responsive to said substantially instantaneouselectric current for producing a level-shifted signal proportional to,but different from, the amplitude of said instantaneous current; meansfor producing a predetermined time delay after a close door command; andmeans for inhibiting the delivery of said first signal value to saidoutput means during said predetermined time delay.
 17. The inventionaccording to claim 16, wherein said means for producing a predeterminedtime delay includes a potentiometer for adjusting the length of saidpredetermined time delay within a predetermined range of values.
 18. Theinvention according to claim 15, further comprising: means for producinga reference signal proportional to the power supply voltage level, andfor providing said reference signal to said first means for monitoring,said first means for monitoring including means for adjusting said firstsignal value produced thereby in order to compensate for fluctuations inthe power supply level.